Models containing age and NIHSS predict recovery of ambulation and upper limb function six months after stroke: an observational study

Questions: What is the incidence of recovery of ambulation and upper limb function six months after stroke? Can measures such as age and the National Institutes of Health Stroke Scale (NIHSS) be used to develop models to predict the recovery of ambulation and upper limb function? Design: Prospective cohort study. Participants: Consecutive sample of 200 people with stroke admitted to a Sydney Hospital. Outcome measures: Ambulation was measured with item 5 of the Motor Assessment Scale (MAS); patients scoring 3 could ambulate independently. Upper limb function was measured with items 7 and 8 of the MAS; patients scoring 5 could move a cup across the table and feed themselves with a spoonful of liquid with the hemiplegic arm. Results: Of the 114 stroke survivors who were unable to ambulate initially, 80 (70%) achieved independent ambulation at six months. Of the 51 stroke survivors who could not move a cup across the table initially, 21 (41%) achieved the upper limb task at six months. Of the 56 stroke survivors who were unable to feed themselves initially, 25 (45%) could feed themselves at six months. Models containing age and severity of stroke (measured with NIHSS) predicted recovery of ambulation and ability to move a cup across the table, whilst a model containing severity of stroke predicted ability to feed oneself. All prediction models showed good discrimination (AUC 0.73 to 0.84). Conclusion: More than two-thirds of people after stroke recovered independent ambulation and less than half recovered upper limb function at six months. Models using age and NIHSS can predict independent ambulation and upper limb function but these prediction models now require external validation before use in clinical practice.